The invention relates to a lacquer composition, obtainable by a treatment of an organosilane compound with water, which organosilane compound comprises at least two hydrolytically-condensable silane substituents, as well as a non-hydrolyzable silane substituent which contains a hydroxy or hydrolyzable group bonded to a carbon atom. The invention also relates to a method of applying a coating of lacquer to a substrate, in particular parts of a shaver, such as a shaver head or a housing.
A lacquer composition of the type mentioned in the opening paragraph is known from a publication by K. Greiwe in Farbe+Lack, 97(11), 1991, pp. 968-971. The known lacquer composition is obtained by treating a mixture of 3-glycidyl-oxypropyltrimethoxysilane (abbr. GLYMO), an alkyl trimethoxysilane, and aluminum tri-sec-butylate with water and a solvent. The resultant lacquer composition is used, inter alia, in a method in which the lacquer composition is sprayed onto a brass surface and cured at 130.degree. C. for 45 minutes. A disadvantage of the known lacquer composition is that it is prepared by means of aluminum tri-sec-butylate as the catalyst. This aluminum compound, which serves as a curing agent for the polymerization of the epoxy group present in GLYMO, has a limited shelf life under ambient conditions. If the curing agent has been in contact with air, the water present in the curing agent causes the effectiveness of the curing agent to be reduced, resulting in lacquer coatings of a non-uniform quality. Storage and handling should take place under water-free conditions, which, from a practical point of view, renders the processing unattractive. Although the aluminum compound plays an essential role in curing the lacquer coating, it has no important function in the cured lacquer coating. Besides, the reactivity of the aluminum compound is such that the treatment with water has to be carried out step by step, while cooling, which renders the preparation of the lacquer composition time-consuming and laborious. For example, the preparation of said lacquer composition on an industrial scale requires a computer-controlled system comprising a cooling unit and a double-walled reaction vessel, with the dosing rate of the starting substances having to be controlled by measuring the temperature of the reaction vessel.
It is known that the reactivity and the water-sensitivity of the aluminum compound can be slightly reduced by replacing a butylate ligand by an ethyl acetoacetate ligand. However, this measure proves to be insufficient to overcome the above-mentioned drawbacks.